Embodiments relate to a semiconductor device and a manufacturing method of the semiconductor device. A lateral double diffused metal oxide semiconductor (LDMOS) is a lateral power device having a rapid switching response and a high input impedance and is configured of a low voltage MOS (LV MOS), a high voltage drain extended MOS (HV DEMOS), etc. as a plurality of carrier devices.
In the case of the DEMOS, in order to process high voltage current, the distance between a gate electrode and a drain region is elongated or a device isolation layer for expanding drain is formed, thereby making breakdown voltage large. However, when an n-region is formed to be elongated between the gate electrode and the drain region, it is difficult to minimize the size of the device when a photolithograpy process is performed to form an n-region ion implantation mask. The mask alignment work is a relatively fine process, introducing many difficulties.
Moreover, when the device isolation layer for expanding drain is formed, problems arise in that on-resistance Ron is increased and current driving ability is significantly reduced. In particular, in the device isolation layer for expanding a drain, a portion adjacent to the gate electrode is weak against high voltage current and a surface breakdown phenomenon may be generated, if an electric field is concentrated thereon.